Heat pump air conditioner with all seasons dehumidifing function

ABSTRACT

An air conditioning system providing (a) Heating and dehumidifying mode, (b) Cooling and dehumidifying mode and (c) Warming mode is disclosed to include a lower layer air passage provided with indoor air inlet and outlet valves and outdoor air inlet and outlet valves, an upper layer air passage provided with indoor air inlet and outlet valves and outdoor air inlet and outlet valves, an intermediate air passage provided with an air valve in communication between the lower layer air passage and the upper layer air passage, and a valve control system adapted to control closing/opening of the valves in the lower layer air passage, upper layer air passage and intermediate air passage.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air conditioning system without four-way valve and, more particularly to an economic and durable air conditioning system, which provides (a) Heating and dehumidifying mode, (b) Cooling and dehumidifying mode, and (c) Warming mode.

2. Description of the Related Art

In Taiwan and many other countries of similar geographical features, people may use an air-conditioner to regulate the temperature and humidity of the house during hot days, and an electric heater to keep the house warm during winter. Actually, using a heat pump air-conditioner to keep the house warm is much energy saving and safer than an electric heater. A heat pump air-conditioner enables hot air to be evenly distributed in the whole space inside the house. When an electric heater is operation, there is a big temperature difference between the remote place in the house and the proximity place close to the electric heater. Uneven distribution of temperature in the house may cause the people feel uncomfortable. An improper use of an electric heater may cause a fire accident. Further, when not in use, the user must find a space to store the electric heater. An air-conditioner with hot air function is more expensive than an air-conditioner without hot air function. However, it is economic to use an air-conditioner with hot air function in a family instead of the use of an air-conditioner without hot air and an electric heater. From the explanation of thermodynamics indicated in FIG. 13, a heat pump air-conditioner saves at least about 70.7% electric energy under hot function in cold seasons in the production of heat energy in comparison with an electric heater. A lowest EER value of commercially available hot/cold dual mode air-conditioners in Taiwan is 2.07 Kcal/hw=2.405 w/w, EER=Q_(L)/W, i.e., cold generation rate Q_(L)=EER×W. Thus hot generation rate Q_(H)=(1+EER)×W>3.405W. When an electric heater is used, it converts 1 W (electric power) into 1 Q (hot generation rate). To produce same amount of hot generation rate Q, a hot/cold dual mode air-conditioner consumes only 1/3.405W i.e., 0.293W. Therefore, heat pump (hot/cold dual mode) air-conditioner saves at least about 70.7% electric energy in the production of heat energy in comparison with an electric heater.

A conventional four-way valve type heat pump air conditioner is capable of providing cold air in hot season and hot air in cold season. FIG. 14 shows the operation of a four-way valve type heat pump air conditioner. During heating mode, the four-way valve is controlled to guide the high pressure and high temperature exhaust refrigerant vapor from the compressor to the heat exchanger inside the room. During the condensation of refrigerant vapor, the heat exchanger expels thermal energy to heat the room air. When the condensed high pressure liquid refrigerant reached the expansion zone, owing to the function of one-way valve (check valve), the refrigerant is only allowed to pass the heating function branch pipe, thereby causing liquid refrigerant to pass through the expansion device then becomes low temperature low pressure mixed saturated liquid and vapor refrigerant. Thereafter, low temperature saturated liquid refrigerant reaches to the outdoor heat exchanger and absorbs heat from outdoor air, and then vaporizes. Vaporized refrigerant is then returned to the four-way valve, and guided into the input side of the compressor. In order to change the operation mode from heating to cooling, the four-way valve is driven to change the position, for enabling exhaust refrigerant vapor from the compressor to the outdoor heat exchanger, where high pressure and high temperature vapor refrigerant is condensed to release heat to outdoor air. Thereafter, refrigerant is only allowed passing through the cooling function branch pipe, thereby causing liquid refrigerant to pass through the expansion device then to become low temperature low pressure mixed saturated liquid and vapor refrigerant. Thereafter, low temperature saturated liquid refrigerant reaches the indoor heat exchanger and absorbs heat from room air, and then vaporizes in the heat exchanger to cool circulating air. Vaporized refrigerant then returns to the four-way valve, and is guided into the input side of the compressor. As indicated, this conventional air conditioner uses a four-way valve with one-way valves to control the flowing direction of refrigerant, enabling the heat exchanger to work as an evaporator or a condenser so as to provide the desired heating or cooling mode. This design of air conditioner has numerous drawbacks. Because the four-way valve is operated at the high-pressure side (the pressure may be as high as 10 atm), thus it fails easily. In comparison with an air-conditioner without heating mode, this design of air conditioner needs additionally four-way valve, two one-way check valves, one more expansion valve, and related pipes. Moreover, FIG. 13 indicates that Q_(H)=W+Q_(L); thus the surface area of heat exchanger with heating function (working as a condenser) must be greater than that of heat exchanger with cooling function (working as an evaporator). However, the heat exchangers of conventional four-valve heat pump air conditioner cannot match the required condition (Q_(H)=W+Q_(L); namely, Q_(H)>Q_(L)) thus it cannot work effectively in either heating or cooling functions. Due to the previously mentioned drawbacks, the service life of a conventional four-valve heat pump air conditioner is practically shorter than an air conditioner with cooling function only.

It is therefore desirable to provide a heat pump air conditioning system, which eliminates the previously mentioned drawbacks.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an air conditioning system, which eliminate the drawbacks of conventional four-way valve type heat pump air conditioners. It is another object of the present invention to provide an air conditioning system, which is cost-effect. It is still another object of the present invention to provide an air conditioning system, which is durable in use as a normal air conditioner with cooling function only. It is still another object of the present invention to provide an air conditioning system, which allows the user to regulate the humidity and temperature of the air inside the house in all seasons through the year.

According to one aspect of the present invention, the air conditioning system comprises a lower and an upper layer air passages. Both the lower and upper layer air passages have an outdoor air inlet, an outdoor air outlet, an indoor air inlet and an indoor air outlet. Moreover, air valves are respectively mounted in all the door air inlets and outlets. An intermediate air door with a close/open valve is installed in the left end of the separate board between the lower and upper passages. Its function is in communication between the upper layer air passage and the lower layer air passage. The present air conditioning system comprises a compressor, a condenser, a liquid accumulator, an expansion valve and an evaporator. The condenser is installed in the lower layer air passage, and the evaporator is installed in the upper layer air passage. The compressor, liquid accumulator and expansion valve are installed in suitable positions outside the lower and upper layer air passages. A fan is installed in the lower layer air passage behind the condenser. A heater is set between the condenser and the fan. A fan is installed in the upper layer air passage behind the evaporator. In addition, a valve control system adapted to control closing/opening of the valves in the lower layer air passage, the upper layer air passage and the intermediate air passage. According to another aspect of the present invention, the air conditioning system provides three modes as follows: (a) Heating and dehumidifying mode: where the valve control system opens the valve of the intermediate air passage, the indoor air inlet valve of the upper layer air passage and the indoor air outlet valve of the lower layer air passage, and at the same time closes the outdoor air inlet valve, outdoor air outlet valve and indoor air outlet valve of the upper layer air passage and the outdoor air inlet valve, outdoor air outlet valve and indoor air inlet valve of the lower layer air passage; during this stage, the upper layer fan causes currents of indoor air from the inside space of the house to pass in direction through the evaporator (where air is cooled and dehumidified) in the upper layer air passage toward the inside of the intermediate air passage, and the lower layer fan draws currents of air from the upper layer air passage into the lower layer air passage to let currents of air be heated by condenser and heater; (b) Cooling and dehumidifying mode: where the valve control system closes the valve of the intermediate air passage, the outdoor air inlet valve and outdoor air outlet valve of the upper layer air passage, and the indoor air inlet valve and indoor air outlet valve of the lower layer air passage, and at the same time opens the indoor air inlet valve and indoor air outlet valve of the upper layer air passage and the outdoor air inlet valve and outdoor air outlet valve of the lower layer air passage, so that indoor air is prohibited from passing to the lower layer air passage inside of the air conditioning system, and outdoor air is prohibited from passing to the upper layer air passage inside of the air conditioning system; during this stage, the upper layer fan causes currents of indoor air to pass through the evaporator (where air is cooled and dehumidified) in the upper layer air passage toward the indoor space of the house, and the lower layer fan draws currents of air from the outdoor space into the lower layer air passage to make a heat exchange with the condenser, and therefore, the air conditioning system outputs cold air and removes humidity from air; and (c) Warming mode: where the valve control system closes the valve of the intermediate air passage, the indoor air inlet valve and indoor air outlet valve of the upper layer air passage, and the outdoor air inlet valve and outdoor air outlet valve of the lower layer air passage, and at the same time opens the outdoor air inlet valve and outdoor air outlet valve of the upper layer air passage and the indoor air inlet valve and indoor air outlet valve of the lower layer air passage, so that outdoor air is prohibited from passing to the lower layer air passage inside of the air conditioning system, and indoor air is prohibited from passing to the upper layer air passage inside of the air conditioning system; during this stage, the upper layer fan causes currents of outdoor air to pass from the outdoor space to the inside of the upper layer air passage to make a heat exchange with the evaporator then flows toward the outdoor space of the house, and the lower layer fan draws currents of indoor air from the house into the lower layer air passage to make a heat exchange with the condenser, the air is heated by the condenser then flows toward the house and makes a warm function.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic bottom view of the upper layer air passage of the air conditioning system under the heating and dehumidifying mode according to the present invention.

FIG. 2 is a schematic bottom view of the lower layer air passage of the air conditioning system under the heating and dehumidifying mode according to the present invention.

FIG. 3 is a schematic front view of the air conditioning system under the heating and dehumidifying mode according to the present invention.

FIG. 4 is a schematic bottom view of the upper layer air passage of the air conditioning system under the cooling and dehumidifying mode according to the present invention.

FIG. 5 is a schematic bottom view of the lower layer air passage of the air conditioning system under the cooling and dehumidifying mode according to the present invention.

FIG. 6 is a schematic front view of the lower layer air passage of the air conditioning system under the cooling and dehumidifying mode according to the present invention.

FIG. 7 is a schematic bottom view of the upper layer air passage of the air conditioning system under the warming mode according to the present invention.

FIG. 8 is a schematic bottom view of the lower layer air passage of the air conditioning system under the warming mode according to the present invention.

FIG. 9 is a schematic front view of the of the air conditioning system under the warming mode according to the present invention.

FIGS. 10(a) and 10(b) illustrate the structure of the front panel and back panel of the main unit of the air conditioning system according to the present invention.

FIGS. 11(a) and 11(b) are schematic drawings showing the air passage arrangement of the split type air conditioning system according to the present invention.

FIG. 12 illustrates the arrangement of the front panel of the main unit of the split type air conditioning system according to the present invention.

FIG. 13 is a schematic drawing indicating the relationship between the heat pump (air conditioning system) and EER.

FIG. 14 is a schematic drawing showing the arrangement of a conventional four-way valve type heat pump air conditioner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1˜3, the basic hardware architecture of an air conditioning system in accordance with the present invention is shown comprising a lower layer air passage a, an upper layer air passage b, an intermediate air passage c in communication between the lower layer air passage a and the upper layer air passage b, a compressor 1, a condenser 2, a liquid accumulator 3, an expansion valve 4, an evaporator 5, a thermostat-controlled heater 6, an upper layer fan 7, and a lower layer fan 8. The lower layer air passage a has an outdoor air inlet a1, an outdoor air outlet a2, an indoor air inlet a3, and an indoor air outlet a4. Air valves a11, a22, a33, a44 are respectively mounted in the outdoor air inlet a1, the outdoor air outlet a2, the indoor air inlet a3, and the indoor air outlet a4. The upper layer air passage b has an outdoor air inlet b1, an outdoor air outlet b2, an indoor air inlet b3, and an indoor air outlet b4. Air valves b11, b22, b33, b44 are respectively mounted in the outdoor air inlet b1, the outdoor air outlet b2, the indoor air inlet b3, and the indoor air outlet b4. The intermediate air passage c is disposed in communication between the air output side of the upper layer air passage b and the air input side of the lower layer air passage a. A valve c1 is installed in the intermediate air passage c, and adapted to close/open the passage between the upper layer air passage b and the lower layer air passage a. In the drawings, reference sign A indicates the outdoor space (outdoor side), and reference sign B indicates the indoor space (indoor side). The evaporator 5 is installed in the upper layer air passage b. The condenser 2 is installed in the lower layer air passage a. The upper layer fan 7 is installed in the upper layer air passage b behind the evaporator 5. The lower layer fan 8 is installed in the lower layer air passage a behind the condenser 2. The thermostat-controlled heater 6 is set between the condenser 2 and the lower layer fan 8.

By means of the control of a valve control system (not shown), the air conditioning system provides three operation modes, namely, heating and dehumidifying mode (in cold and wet days), cooling and dehumidifying mode (in hot days), and warming mode (in cold days). The design of the present invention is practical for use in window type air conditioners as well as split type air conditioners.

EXAMPLE 1 Window Type Air-Conditioner

(1) Heating and Dehumidifying Mode (See FIGS. 1˜3 and 10):

Turn the function selector of the control panel at the front panel 200 of the main unit of the window type air-conditioner shown in FIG. 10(a) to the position of “HEAT.DEHUMIDIFIER” and the fan control to the desired fan amount. At this time, the valve control system opens the valve c1 of the intermediate air passage c, the indoor air inlet valve b33 of the upper layer air passage b, and the indoor air outlet valve a44 of the lower layer air passage a, and at the same time closes the outdoor air inlet valve b11, outdoor air outlet valve b22 and indoor air outlet valve b44 of the upper layer air passage b and the outdoor air inlet valve all, outdoor air outlet valve a22 and indoor air inlet valve a33 of the lower layer air passage a. Thus, the air conditioning system is isolated from outdoor air. During this stage, the upper layer fan 7 causes currents of indoor air to pass in direction from the inside of the house through the evaporator 5 (where currents of air are dehumidified due to the effect of the evaporator 5) in the upper layer air passage b toward the inside of the intermediate air passage c; the lower layer fan 8 draws currents of air from the upper layer air passage b into the lower layer air passage a where currents of air are heated due to the effect of the condenser 2. If the temperature of output air is still below the desired level, start the thermostat-controlled heater 6 to heat air to the desired temperature level.

(2) Cooling and Dehumidifying Mode (See FIGS. 4˜6 and 10):

Turn the function selector of the control panel at the front panel 200 of the main unit of the window type air conditioner to the position of “COLD”, the fan control to the desired fan amount, and the temperature control to the desired temperature level. At this time, the valve control system closes the valve c1 of the intermediate air passage c, the outdoor air inlet valve b11 and outdoor air outlet valve b22 of the upper layer air passage b, and the indoor air inlet valve a33 and indoor air outlet valve a44 of the lower layer air passage a, and at the same time opens the indoor air inlet valve b33 and indoor air outlet valve b44 of the upper layer air passage b and the outdoor air inlet valve all and outdoor air outlet valve a22 of the lower layer air passage a. Thus, the upper layer air passage b of the air conditioning system is isolated from outdoor air, and outdoor air is allowed to pass into the inside the lower layer air passage a of the air conditioning system. Therefore, indoor air is prohibited from passing to inside the lower layer air passage a of the air conditioning system, and outdoor air is prohibited from passing to the inside the upper layer air passage b of the air conditioning system. During operation, the upper layer fan 7 causes currents of indoor air from the house to pass through the evaporator 5 (where the air is cooled and dehumidified) in the upper layer air passage b then flows toward the indoor space of the house; the lower layer fan 8 draws currents of air from the outdoor space into the lower layer air passage a to make a heat exchange with the condenser 2. Due to the effect of the evaporator 5, moisture is removed from the currents of air and air is cooled as well. Further, the condenser 2 condenses refrigerant during circulation of outdoor air. Therefore, the air conditioning system outputs cold air, and removes humidity from air.

(3) Warming Mode (see FIGS. 7˜10):

Turn the function selector of the control panel at the front panel 200 of the main unit of the window type air conditioner to the position of “HOT”, the fan control to the desired fan amount, and the temperature control to the desired temperature level. At this time, the valve control system closes the valve c1 of the intermediate air passage c, the indoor air inlet valve b33 and indoor air outlet valve b44 of the upper layer air passage b, and the outdoor air inlet valve all and outdoor air outlet valve a22 of the lower layer air passage a, and at the same time opens the outdoor air inlet valve b11 and outdoor air outlet valve b22 of the upper layer air passage b and the indoor air inlet valve a33 and indoor air outlet valve a44 of the lower layer air passage a. Thus, outdoor air is prohibited from entering into the lower layer air passage a and, indoor air is prohibited from passing to the inside the upper layer air passage b of the air conditioning system. During operation, the upper layer fan 7 causes currents of outdoor air from the outdoor space to the inside of the upper layer air passage b through the evaporator 5 (where the refrigerant is heated by outdoor air and vaporizes) toward the outdoor space of the house; the lower layer fan 8 draws currents of indoor air from the house into the lower layer air passage a through the condenser 2 (where the air is heated) toward the indoor space of the house. Due to the effect of the evaporator 5, circulating refrigerant is heated by outdoor air, and currents of indoor air are heated by the hot circulating refrigerant in the condenser 2 and creates a warm function.

Further, air sealing hoods 9 are provided in the upper layer air passage a and the lower layer air passage b around the respective valves to prevent air leakage and to guide flows of air. If only valve dampers are used without the air sealing hoods 9, eddy flow energy loss will occur. When selecting the heating and dehumidifying mode or the warming mode, the user can set the thermostat-controlled heater 6 subject to the desired temperature level. FIGS. 10(a) and 10(b) show the arrangement of the front panel 200 and back panel 300 of the window type air conditioner. The aforesaid compressor 1, liquid accumulator 3, expansion valve 4 and valve control system are set in suitable positions between the front panel 200 and the back panel 300.

EXAMPLE 1I Split Type Air-Conditioner (See FIGS. 11 and 12)

According to this example, the main unit 100 is installed in the outdoor space A, and the control panel f of the front panel 200 of the main unit 100 is disposed in the indoor space B and electrically connected to the internal circuit of the main unit 100 by electric wires g. Similar to the aforesaid first example, the split type air-conditioner provides heating and dehumidifying mode, cooling and dehumidifying mode, and warming mode in the same manner. The front panel of the main unit 100 has only upper and lower layer indoor air inlets b3 and a3 and upper layer and lower layer indoor air outlets b4 and a4. An upper layer air inlet connector bb3 and a lower layer air inlet connector aa3 are respectively installed in the upper and lower layer indoor air inlets b3 and a3. An upper layer air inlet air hose h3 and a lower layer air inlet air hose h2 are respectively connected to the upper layer air inlet connector bb3 and the lower layer air inlet connector aa3. The upper layer air inlet air hose h3 and the lower layer air inlet air hose h2 have the respective opposite end respectively connected to a three-way air inlet conduit E2. The three-way air inlet conduit E2 has an air inlet end connected to an indoor air inlet conduit h1, which is in turn connected to an air inlet port k in the ceiling B1 in the indoor space B. An upper layer air outlet connector bb4 and a lower layer air outlet connector aa4 are respectively installed in the upper and lower layer indoor air outlets b4 and a4. An upper layer air outlet air hose j2 and a lower layer air outlet air hose j3 are respectively connected to the upper layer air outlet connector b4 and the lower layer air outlet connector a4. The upper layer air outlet air hose j2 and the lower layer air outlet air hose j3 have the respective opposite end respectively connected to a three-way air outlet conduit E1. The three-way air outlet conduit E1 has an air outlet end connected to an indoor air outlet conduit j1, which is in turn connected to an air outlet port m in the ceiling B1 in the indoor space B. In FIGS. 11 and 12, the reference sign B2 indicates the floor of the house.

During operation, indoor air is sucked into the indoor air inlet conduit h1 through the air inlet port k in the ceiling B1 in the door space B subject to the operation mode selected (the heating and dehumidifying mode, the cooling and dehumidifying mode, or the warming mode). When air sucked into the indoor air inlet conduit h1, it flows through the three-way conduit E2 and the upper or lower layer air inlet connector bb3 or aa3 to the upper or lower layer indoor air inlet b3 or a3. The other circulation path is same as the aforesaid Example I. Further, when passed out of the upper or lower layer indoor air outlet b4 or a4, air flows through the upper or lower layer indoor air outlet b4 or a4 to the indoor air outlet conduit j1 through the three-way air outlet conduit E1, and then flows to the indoor space B via the air outlet port m in the ceiling B1.

As indicated above, the invention provides an air conditioning system, which matches the requirement of the heat exchanger area of condenser must be greater than that of evaporator and is durable in use and, which allows the user to dehumidify the air and regulate the indoor temperature to the comfortable level in all seasons through the year. Because this air conditioning system owns the functions of combination of a conventional heat pump air conditioner and a dehumidifier, the application of the invention saves much money and energy consumption. FIG. 13 shows that the present air conditioner of the invention when uses the warm function may save at least about 70.7% electric energy in the production of heat energy Q in comparison with an electric heater. Therefore, the use of the present invention in cold days to keep the house warm instead of an electric heater saves much electricity. In general, the invention has much industrial value.

A prototype of air conditioning system has been constructed with the features of FIGS. 1˜13. The air conditioning system functions smoothly to provide all of the features as discussed before.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

1. An air conditioning system comprising: a lower layer air passage, said lower layer air passage having an outdoor air inlet, an outdoor air outlet, an indoor air inlet, an indoor air outlet, and air valves respectively mounted in said outdoor air inlet, said outdoor air outlet, said indoor air inlet and said indoor air outlet; an upper layer air passage, said upper layer air passage having an outdoor air inlet, an outdoor air outlet, an indoor air inlet, an indoor air outlet, and air valves respectively mounted in said outdoor air inlet, said outdoor air outlet, said indoor air inlet and said indoor air outlet; an intermediate air passage in communication between said lower layer air passage and said upper layer air passage, said intermediate air passage having installed therein a valve adapted to close/open the passage between said upper layer air passage and said lower layer air passage; a compressor; a condenser installed in said lower layer air passage; a liquid accumulator; an expansion valve; an evaporator installed in said upper layer air passage; a heater set between said condenser and said lower layer fan; an upper layer fan installed in said upper layer air passage behind said evaporator; a lower layer fan installed in said lower layer air passage behind the condenser; and a valve control system adapted to control closing/opening of the valves in said lower layer air passage, said upper layer air passage and said intermediate air passage.
 2. The air conditioning system as claimed in claim 1, which provides three modes: (a) Heating and dehumidifying mode: where the valve control system opens the valve of said intermediate air passage, the indoor air inlet valve of said upper layer air passage, and the indoor air outlet valve of said lower layer air passage, and at the same time closes the outdoor air inlet valve, outdoor air outlet valve and indoor air outlet valve of said upper layer air passage and the outdoor air inlet valve, outdoor air outlet valve and indoor air inlet valve of said lower layer air passage; during this stage, said upper layer fan causes currents of indoor air to pass in direction from the inside of the house through said evaporator where air can be dehumidified in said upper layer air passage toward the inside of said intermediate air passage, and said lower layer fan draws currents of air from said upper layer air passage into said lower layer air passage through said condenser and said heater to let currents of air be heated then guided toward the house; (b) Cooling and dehumidifying mode: where said valve control system closes the valve of said intermediate air passage, the outdoor air inlet valve and outdoor air outlet valve of said upper layer air passage, and the indoor air inlet valve and indoor air outlet valve of said lower layer air passage, and at the same time opens the indoor air inlet valve and indoor air outlet valve of said upper layer air passage and the outdoor air inlet valve and outdoor air outlet valve of said lower layer air passage, so that indoor air is prohibited from passing to said lower layer air passage inside of the air conditioning system, and outdoor air is prohibited from passing to said upper layer air passage inside of the air conditioning system; during this stage, said upper layer fan causes currents of indoor air to pass through said evaporator where air can be cooled and dehumidified in said upper layer air passage toward the indoor space of the house, and said lower layer fan draws currents of outdoor air from the outdoor space into said lower layer air passage to make a heat exchange with said condenser then to flow toward outdoor space, and therefore, the air conditioning system outputs cold air and removes humidity from air; and (c) Warming mode: where said valve control system closes the valve of said intermediate air passage, the indoor air inlet valve and indoor air outlet valve of said upper layer air passage, and the outdoor air inlet valve and outdoor air outlet valve of said lower layer air passage, and at the same time opens the outdoor air inlet valve and outdoor air outlet valve of said upper layer air passage and the indoor air inlet valve and indoor air outlet valve of said lower layer air passage; during this stage, said upper layer fan causes currents of outdoor air to pass from the outdoor space to the inside of said upper layer air passage through said evaporator to make a heat exchange then toward the outdoor space of the house, and said lower layer fan draws currents of indoor air from the house into said lower layer air passage to make a heat exchange with said condenser where the air is heated then the hot air flows toward house.
 3. The air conditioning system as claimed in claim 1, wherein said intermediate air passage is disposed in communication between the air output side of said upper layer air passage and the air input side of said lower layer air passage.
 4. The air conditioning system as claimed in claim 1, wherein said heat is a thermostat-controlled heater that can be adjusted to heat air to one of a series of temperature levels.
 5. The air conditioning system as claimed in claim 2, wherein said heater is controllable to heat air to the desired temperature level during Heating and dehumidifying mode.
 6. The air conditioning system as claimed in claim 1, further comprising air sealing hoods provided in said upper layer air passage and said lower layer air passage around the respective valves to prevent air leakage and to guide flows of air.
 7. The air conditioning system as claimed in claim 1, which is a split type air conditioning system having the main unit installed in the outside of the house with the control panel of the main unit disposed in the inside the house and electrically connected to the internal circuit of the main unit by electric wires wherein front panel of the main unit having upper and lower layer indoor air inlets and upper layer and lower layer indoor air outlets, an upper layer air inlet connector and a lower layer air inlet connector respectively installed in said upper and lower layer indoor air inlets, an upper layer air inlet air hose and a lower layer air inlet air hose respectively connected to said upper layer air inlet connector and said lower layer air inlet connector, said upper layer air inlet air hose and said lower layer air inlet air hose having a respective opposite end respectively connected to a three-way air inlet conduit, said three-way air inlet conduit having an air inlet end connected to an indoor air inlet conduit, which is in turn connected to an air inlet port in the ceiling inside the house, an upper layer air outlet connector and a lower layer air outlet connector respectively installed in said upper and lower layer indoor air outlets, an upper layer air outlet air hose and a lower layer air outlet air hose respectively connected to said upper layer air outlet connector and said lower layer air outlet connector, said upper layer air outlet air hose and said lower layer air outlet air hose having a respective opposite end respectively connected to a three-way air outlet conduit, said three-way air outlet conduit having an air outlet end connected to an indoor air outlet conduit, which is in turn connected to an air outlet port in the ceiling inside the house. 